Vehicle Search and Seizure Laws Basics

A police officer conducting a traffic stop may search your vehicle and seize evidence without a warrant under certain conditions. The Fourth Amendment to the U.S. Constitution protects citizens from unreasonable search and seizure, but interpretations of "reasonableness" have changed throughout history. Under the exclusionary rule, the prosecution cannot use any evidence or information obtained from an illegal vehicle search.

The line between lawful and unlawful vehicle searches can seem a bit blurry, and is frequently redefined by courts, so understanding the law is in every motorist's best interests. This article provides the basics of vehicle search and seizure laws after a traffic stop.

When Vehicle Searches are Legal

Generally, an officer may conduct a search of your vehicle under one of the following conditions:

You consent to a search

The officer has probable cause to suspect the existence of incriminating evidence in your vehicle

The officer reasonably believes that a vehicle search is necessary for his or her own protection (i.e. suspicion of a concealed weapon)

You have been arrested

An officer may ask to search your vehicle without a warrant even if he or she is not authorized to do so. But motorists always have the right to say no, and illegal searches can be challenged later in court. If you consent to a search, however, any evidence obtained may be used against you.

In most states, search and seizure rules pertaining to automobiles are not as strict as those relating to one's home. For example, an officer may conduct a warrantless search of those areas immediately within the driver's reach, which includes the glove compartment and the vicinity of the front seat, if the officer suspects weapons or other potential immediate threats.

An officer who stops a motorist for a minor infraction, such as a speeding violation, generally may not conduct a search (unless, as noted above, there is reason to believe one or more of the car’s occupants is armed or otherwise dangerous).

The "Plain View" Doctrine

Under the plain view doctrine, officers may lawfully seize evidence of a crime without a search warrant if it's in plain view. For example, if an officer sees a glass pipe with what appears to be drug residue in the backseat after stopping a motorist for running a red light, the officer may seize the pipe. The officer may also lawfully conduct a warrantless search for other drug-related items in the automobile after finding the glass pipe, since it provides probable cause that other incriminating evidence may be present.

The officer may not, however, search the vehicle indiscriminately. For example, an officer who sees an illegal weapon in plain view and subsequently finds a small packet of drugs in the motorist's wallet likely has overstepped his or her boundaries. The search following the discovery of the illegal weapon must be weapon-related, so it's unreasonable to search someone's wallet because it could not reasonably contain a weapon.

The plain view doctrine also extends to evidence that an officer or drug-sniffing dog smells or hears after a traffic stop.

How a Frisk Differs from a Search

An officer is permitted to conduct a frisk, in which an individual's clothing is patted down, if the officer has a reasonable suspicion that the driver or passengers are armed or otherwise pose a threat. The purpose of the frisk is to ensure the officer's safety; it is not considered a search within the meaning of the Fourth Amendment.

However, an officer conducting a frisk for weapons may not manipulate objects in pockets or otherwise investigate further. To do so would be considered a search.

For example, if an officer conducting a frisk comes across an object that feels suspiciously like a hypodermic needle, he or she may pull it out of the suspect's pocket and seize it. But if the officer conducting a frisk were to poke a finger into an otherwise unassuming bulge, thus discovering a powdery residue resembling heroin, that evidence would be inadmissible.